<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .top{
            margin: 10px auto;
            width: 1200px;
            /* height: 300px; */
            background-color: red;
            /* 同样可以清除浮动影响 */
            overflow: hidden;
        }
        .left{
            width: 200px;
            height: 300px;
            background-color: rgb(69, 136, 230);
            float: left;
        }
        .right{
            width: 950px;
            height: 300px;
            background-color: pink;
            float: right;
        }
        .bottom{
            height: 100px;
            background-color: rgb(136, 230, 167); 
        }
        /* 清除浮动影响 */
        .clearfix{
            clear: both;
        }
    </style>
</head>
<body>
    <div class="top">
        <div class="left"></div>
        <div class="right"></div>
        <div class="clearfix"></div>
    </div>
    <div class="bottom"></div>
</body>
</html>